Quoth [EMAIL PROTECTED] (David Fetter):
> On Tue, Aug 01, 2006 at 12:37:48PM -0500, Jim C. Nasby wrote:
>> On Sun, Jul 30, 2006 at 11:27:33AM -0400, Tom Lane wrote:
>> > David Fetter <[EMAIL PROTECTED]> writes:
>> > > On Sat, Jul 29, 2006 at 09:44:10PM -0400, Tom Lane wrote:
>> > >> The correct solution is for client-side libraries to provide
>> > >> the feature.
>> > 
>> > > Not if the app is written in SQL, as the bootstrap, regression
>> > > test, etc. code for modules frequently is.
>> > 
>> > SQL doesn't really have any conditional ability strong enough to
>> > deal with existence or non-existence of features.  What are you
>> > hoping to do, a CASE expression?  Both arms of the CASE still have
>> > to parse, so I remain unconvinced that there are real world uses.
>
> CREATE OR REPLACE FUNCTION version_new_enough(
>     in_version INTEGER
> )
> RETURNS BOOLEAN
> LANGUAGE sql
> AS $$
> SELECT
>     COALESCE(
>         s.setting::INTEGER, /* Cast setting to integer if it's there */
>         $1 - 1              /* Otherwise, guarantee a lower number than the 
> input */
>     ) >= $1
> FROM
>     (SELECT 'server_version_num'::text AS name) AS foo
> LEFT JOIN
>     pg_catalog.pg_settings s
>     ON (foo.name = s.name)
> $$;
>
>> There's also plpgsql, which afaik has no way to get the version
>> number (other than slogging though the output of version()).
>
> Right.  String-mashing is great when you have to do it, but this patch
> sets it up so you don't have to. :)

There's *some* data to be gotten from
  select setting from pg_catalog.pg_settings where name = 'server_version';

Seems to me that value isn't without its uses...

[EMAIL PROTECTED]:pgsql-HEAD/doc/src/sgml> for port in 5432 5533 5532 5882; do 
for> psql -p $port -h localhost -d template1  -c "select '$port',
setting from pg_catalog.pg_settings where name like 'server_version';"
for> done
 ?column? | setting 
----------+---------
 5432     | 7.4.13
(1 row)

 ?column? | setting 
----------+---------
 5533     | 7.4.10
(1 row)

 ?column? | setting 
----------+---------
 5532     | 8.0.5
(1 row)

 ?column? | setting  
----------+----------
 5882     | 8.2devel
(1 row)

If I wanted to, it oughtn't be difficult to "string smash" those
settings into something very nearly useful...
-- 
"cbbrowne","@","gmail.com"
http://linuxfinances.info/info/rdbms.html
">in your opinion which is the best programming tools ?
The human brain and a keyboard." -- Nathan Wagner

---------------------------(end of broadcast)---------------------------
TIP 9: In versions below 8.0, the planner will ignore your desire to
       choose an index scan if your joining column's datatypes do not
       match

Reply via email to